Giải thích các bước giải:
Ta có:
\(\begin{array}{l}
\dfrac{{a\sqrt b + b\sqrt a }}{{\sqrt {ab} }}:\dfrac{1}{{\sqrt a - \sqrt b }}\\
= \dfrac{{{{\sqrt a }^2}.\sqrt b + {{\sqrt b }^2}.\sqrt a }}{{\sqrt a .\sqrt b }}.\dfrac{{\sqrt a - \sqrt b }}{1}\\
= \dfrac{{\sqrt a .\sqrt b .\left( {\sqrt a + \sqrt b } \right)}}{{\sqrt a .\sqrt b }}.\left( {\sqrt a - \sqrt b } \right)\\
= \left( {\sqrt a + \sqrt b } \right).\left( {\sqrt a - \sqrt b } \right)\\
= {\sqrt a ^2} - {\sqrt b ^2}\\
= a - b
\end{array}\)
